I'm at a complete loss, having searched all over the place and tried to get help on IRC. I booted the installer from a usb drive, and began installation.
When I detect disks, it asks me if I want to enable the detected RAID array. I choose yes, because I have a RAID0 set up in my motherboard's bios raid driver (which currently holds my windows7 installation and my (now broken) mbr). When I choose partition disks, it can see all partitions including those of Win7. I choose the free space and create a new partition automatically, everything in one partition.
When I move on to install the system, normal or live, it tells me "Installation step failed" without so much as a description or error. When I choose to install GRUB, it asks me to first complete "install base system" or "install system". When I choose base system, it seems to copy or download files and then it fails while installing grub again. On that particular step, I get asked where I want to install the bootloader. /dev/mapper is the default input, but neither that or /dev/sda or sdb etc works.
Any help is much appreciated, I'm clueless
EDIT: I finished installation without bootloader, rebooted and got into grub rescue. Then I used https://help.ubuntu.com/community/Grub2#Command_Line_and_Rescue_Mode instructions, and upon running "boot" it send me to a prompt mentioning "BusyBox". Prompt is (initramfs)